The purpose of this study is to evaluate the effect of GSK2448761 on CYP450 metabolic probes and to evaluate the 2-way interaction between GSK2448761 and two ritonavir-boosted protease inhibitors that are commonly used in HIV-infected subjects.

A Phase I Study to Evaluate the Effect of Darunavir/Ritonavir and Lopinavir/Ritonavir on GSK2248761 Pharmacokinetics and to Assess the Effect of GSK2248761 on CYP450 Probe Drugs in Healthy Adult Subjects

Current or chronic history of liver disease, or known hepatic or biliary abnormalities (with the exception of Gilbert's syndrome or asymptomatic gallstones).

Subjects with a pre-existing condition interfering with normal gastrointestinal anatomy or motility, hepatic and/or renal function, that could interfere with the absorption, metabolism, and/or excretion of the study drugs. Subjects with a history of cholecystectomy should be excluded.

The subject has participated in a clinical trial and has received an investigational product within the following time period prior to the first dosing day in the current study: 30 days, 5 half-lives or twice the duration of the biological effect of the investigational product (whichever is longer).

The subject has received GSK2248761 in a previous clinical trial.

Use of prescription or non-prescription drugs, including vitamins, herbal and dietary supplements (including St John's Wort) within 7 days (or 14 days if the drug is a potential enzyme inducer) or 5 half-lives (whichever is longer) prior to the first dose of study medication, unless in the opinion of the Investigator and GSK Medical Monitor the medication will not interfere with the study procedures or compromise subject safety.

History of sensitivity to any of the study medications, or components thereof or a history of drug or other allergy that, in the opinion of the investigator or GSK Medical Monitor, contraindicates their participation.

Where participation in the study would result in donation of blood or blood products in excess of 500 mL within a 56 day period.

Has a known intolerance or hypersensitivity to aspirin, NSAIDS, or benzodiazepines, or a known intolerance to the active and/or inactive ingredients in dextromethorphan, midazolam and flurbiprofen (Cohort 1 only)

Has any condition or symptom contraindicated for administration of the study drugs: dextromethorphan, midazolam and flurbiprofen. The Investigator should reference the product information of each study drug. (Cohort 1 only)

History of sensitivity to heparin or heparin-induced thrombocytopenia (if heparin is used to maintain the patency of an intravenous cannula).

Pregnant females as determined by positive serum hCG test at screening or prior to dosing.

Lactating females.

The subject's systolic blood pressure is outside the range of 90-140mmHg, or diastolic blood pressure is outside the range of 45-90mmHg or heart rate is outside the range of 50-100bpm for female subjects or 45-100 bpm for male subjects at Screening and Day -1.

Cardiac conduction abnormalities denoted on a single 12-lead ECG at screening or Day -1

Contacts and Locations

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study.
To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below.
For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00920088